Is this battery genuine Dell?

There's no way to verify authenticity by checking a label.  Labels are trivial to counterfeit (it's not like Dell uses any special holograms or anything on theirs) and Dell has changed the label designs on their power adapters over the years too.  The bottom line is that some counterfeits have gotten extremely good at mimicking the genuine product, so if you buy from somewhere other than Dell, there's no easy way and possibly no practical way to tell whether the product you got is genuine.  Whether that uncertainty is worth however much you saved buying somewhere else is of course up to you.